President Barack Obama nominated Mark as United States Ambassador to New Zealand and Samoa in 2014. While serving in New Zealand, Ambassador Gilbert was awarded the Navy's Distinguished Public Service Award – the U.S. military's highest civilian honor – for "exceptional service" and for "presiding over a historic strengthening of the Navy's and Marine Corps' relationship with New Zealand."

Ambassador Gilbert formerly served as a Managing Director of UBS, the culmination of a successful 29-year career in finance. Prior to his banking career, he played professional baseball for eight seasons, reaching the major leagues with the Chicago White Sox in 1985. Mark is the only former major league player to become a United States Ambassador. Ambassador Gilbert served on the Development Committee and Utah Advisory Board of the Sundance Institute; has served as Chairman of the Board at the Pine Crest School; and as President of B'nai Torah Congregation.